Excavators



Aug. 4, 1964 R. o. BILLINGS EXCAVATORS 2 Sheets-Sheet 1 Filed Dec. l5, 1961 ROY O. BILL INGS @ma *ZML ATTORNEYS.

All@ 4, 1964 R. o. BILLINGS 3,143,228

EXCAVATORS Filed Dec. l5, 1961 2 Sheets-Sheet 2 ATTORNEYS.

United States Patent O 3,143,223 EXCAVATORS Roy 0. Billings, Box 2611, Milwaukee, Wis. Filed Dec. 15, 1961, Ser. No. 159,577 16 Claims. (Cl. 214-147) This invention relates to improvements in excavators, and more particularly to a novel earth excavating machine having the advantages of both a conventional clamshell type excavator and a so-called backhoe, and having further advantages and features not associated with either of said presently-available machines.

Conventional clam-shell excavators usually consist of a large, cumbersome crane having a clam-shell type bucket suspended from a movable boom by cables. With such machines the digging force is provided by the weight of the bucket itself and the entire structure must therefore be of substantial size and weight in order to provide suiiicient digging force. Such machines have a large lifting capacity but their size and immobility makes them impractical for digging pipe line trenches or the like, wherein maneuverability of the excavator is important.

The backhoe type of excavator, sometimes called a pull shovel or hoe, is mounted on a truck or similar transport vehicle and is used for excavating ditches and many similar jobs wherein the use of a cumbersome clamshell excavator is impractical. This type of machine includes a so-called dipstick which is pivotally carried on the outer end of a boom, the latter being rigidly mounted on the truck, and there is a hoe-like digging implement on the end of said dipstick. In operation the dipstick is pivoted in a vertical plane about its connection with the boom, thus causing the hoe to gather the soil in an arcuate, scraping movement. While backhoes are more mobile and versatile than the relatively large and cumbersome clam-shell excavators, they are less ei'licient and do not have the digging capacity of the latter. Moreover, because the boom is rigidly mounted on the transport vehicle, said vehicle must be in alignment with the trench during the digging operation, which is not always possible when working on uneven terrain or when there are obstacles present. Also, due to the rigid mounting of the backhoe on its transport vehicle, any shocks or jolts resulting when the digging implement strikes an underground rock or root are transmitted through the entire structure, and the unit must therefore be of extra heavy and expensive construction in order to withstand such shocks.

A further shortcoming of the conventional backhoe is that because the digging implement follows an arcuate digging and lifting path, as described, it is diiiicult to maintain a grade in a trench without moving the truck frequently, and it is impossible to dig straight down, as is desired when repairing leaks in the underground water or gas lines, or the like.

With the above considerations in mind, the principal objects of the present invention are to provide an improved excavating machine which combines certain features of both the clam-shell and backhoe types of excavators, but which improved machine is lighter, less expensive in construction, less expensive to operate, more eiiicient, and which is designed to perform a greater variety of operations than either of said conventional machines.

A more specific object of the present invention is to provide an improved excavating device which is mounted on a mobile truck or tractor crawler, like a backhoe, but wherein the bucket is of the clam-shell type, thus obtaining the increased efficiency and digging capacity of a clam-shell excavator.

3,143,228 Patented Aug. 4, 1964 ICC A further specific object is to provide a novel excavator having a clam-shell type digging bucket which is connected to the boom by exible coupling means, but wherein unlike conventional clam-shell excavators, positive digging force can be applied to said bucket, thus permitting the use of a lighter, less-expensive structure.

A further object of the invention is to provide an improved excavator wherein the entire digging unit is pivotally movably mounted on its transport vehicle, thus allowing the device to be used for digging corners in excavations, for working in close or congested areas, or for other operations not possible with presently-available machines.

Still further objects of the present invention are to provide a novel excavator which is generally similar to a backhoe in design, but which has a clam-shell type digging implement, which improved excavator is adapted to hold a grade in a trench four to ve times longer than a conventional backhoe without necessitating moving the vehicle, which excavator can dig straight down, which is not as susceptible to the jarring effect of underground obstructions, and with which improved excavator the bucket can be readily emptied into a receptacle without necessitating the shifting or tedious maneuvering of the transport vehicle.

With the above and other objects in view, which other objects and advantages will become apparent in the following detailed description, the invention consists of the improved excavator and all of its parts and combinations as set forth in the specification and claims. However, it is to be understood that the invention is not to be limited to the details illustrated and described but includes all such variations or modications as come within the spirit of the invention.

In the accompanying drawings, wherein the same reference numerals designate the same parts in all of the views:

FIG. 1 is a fragmentary side elevational view of the improved excavator and showing, in broken lines, the digging unit in various operative positions;

FIG. 2 is an enlarged fragmentary side elevational view showing the boom, the dipstick, and the bucket assemblage, parts thereof being broken away and shown in section;

FIG. 3 is a top view of the digging bucket in its open condition, taken along line 3-3 0f FIG. 1;

FIG. 4 is a sectional view of the bucket together with its opening and closing mechanism, taken along line 4 4 of FIG. 3; and

FIG. 5 is a top plan view of the boom and dipstick assemblage.

Referring now more particularly to the drawings, the numeral 10 in FIG. 1 designates a portion of a truck or other transport vehicle having a rotatable platform or table 11 thereon and there being a boom 12 vertically pivotally mounted on and projecting outwardly from said platform. The rotatable nature of said platform 11 together with the pivotal mounting of said boom 12 permits universal movement of the entire digging unit, as will be hereinafter seen, and the hydraulic actuating and control means for said members are conventional and need not be described herein.

The boom 12 is formed of two spaced, parallel arms and has its inner end angled downwardly and pivotally secured to the rotatable platform 11 on the truck by means of a bracket and transverse bolt assemblage 13. A single-acting hydraulic cylinder and ram 16 is mounted on the upper surface of said boom, being rigidly secured to the outer end thereof, and the inner, free end of said ram is provided with a double sheave 15 and 15 which is designed to move longitudinally inwardly along said boom when said ram is extended. A pair of coaxial sheaves and 21 are permanently mounted on the outer end of said boom, and spaced inwardly a short distance therefrom is a sheave 64 which lies in a horizontal plane.

Pivotally secured to the outer end of the boom 12 is a sleeve bearing 22 (FIG. 2), and slidably carried in said sleeve is the dipstick 24 employed in the present invention. Adouble-acting hydraulic ram 32 on the underside of the boom is connected to said sleeve as at 33 and is adapted to swing the same, together with the dipstick, in a vertical plane about the transverse pin 35 connecting Asaid sleeve to the boom.

A sheave 26 is mounted on the upper end of the dipstick 24 and the lower end of said dipstick is in the form of an enlarged foot 28 having a convex bottom surface and having an aperture 3i) therethrough communicating with the hollow interior of said dipstick. Within the lowerportion of said hollow dipstick is a pin 34 about which an expansion spring 36Vis anchored, said spring depending to a point adjacentthe lower end of said dipstick. A chain link 38 is secured to the end of said spring 36 and additional links 39 and 40 are connected to said first link and normally depend below the foot 28 on the lower end of the dipstick, the middle link 39 being somewhat smaller than the links 38 and 4t), and said chain links supporting the digging bucket employed in the present invention, as will be described. As appears in FIG. 2, a transverse pin 37 is inserted through aligned apertures 37 in the lower end portion of the dipstick and is pro- `jected through the uppermost link 38. In the preferred form of the invention pairs of said apertures 37 are spaced 90 and said pin 37 can be manually withdrawn and reinserted in selected pairs of said apertures, thus providing simple means for rotating the links and digging bucket to coincide with the particular trenching operation.

'Ihe digging bucket is suspended from the dipstick by the links 38, 39, and 40, as described, there being an apertured top member 42 on said bucket through which the link 40 normally projects, and there being an expansion spring 48 within the bucket body 46 connected to saidlink, and there beinga load carrying pi11 48' extending through the link 40 and anchored at its ends to the bucket body 46. The top surface of the bucket is providedv with a plurality of radial shoulders 44 which are angled upwardly and radially outwardly and which are 'designed to provide a'seat for the convexly-shaped dipstick foot 28 during the digging operation as will be described.k Y

Pivotally secured to the lower portion of the bucket body 46 are a pair of clam shell or bowl elements 50 and 51 which are secured to the body by transverse pins 52 located adjacent the upper edges of said bowl elements intermediate their lengths. The design and pivotal mounting of said bucket elements 50 and 51 permits the same to pivotV from a closed position as shown in full lines and designated by the letter A in FIG. l to the various open positions illustrated by broken lines and designated by the 'letters B, C, and D. A pair of double-acting hydraulic Y cable 59 is trained about the aforementioned sheave 21 on the outer end of the boom, the inner end of said cable being connected to a power-driven winch or other suitable winding device 59 on the truck. Said cable 59, hereinafter referred to as the hoist line, extends downwardly along the dipstick and the lower end of said line is secured to the foot 28 at the bottom of the 'dipstick as at 60.V A four part cable or line 62 is secured to the outer end of the boom at 61 and extends inwardly there along and around the sheave 15', forwardly and around the horizontal sheave 64, rearwardly again and around the sheave 15, and forwardly and under the sheave 20. Said line 62 is then carried upwardly along the dipstick, about the sheave 26, and is anchored to the sleeve 22 as at 66. Thus, when the hydraulic ram 16 is extendedV and the double sheave member 15 moved inwardly therewith, the dipstick 24 will be forcibly lowered through the sleeve bearing 22.

In the operation of the novel excavator comprising the present invention, the truck or other vehicle on which the unit is mounted is first positioned adjacent the area to be excavated. The rotatable table 11 on said truck is then rotated to position the boom 12 over the approximate. digging area and the hoist line 59 is operated to produce the desired boom angle.

The double-acting hydraulic ram 32 on the underside of the boom is then actuated to swing the sleeve bearing 22 about its pivot connection and to thereby position and lock the dipstick 24 at a desired angle relative to the boom. Next, the dipstick is urged downwardly through said sleeve (positions B and C in FIG. 1), by means of the aforementioned ram 16 and line 62, to lower the digging bucket toward the designated point on the ground or to extend it for remote digging (position C), said bucket being lin its open condition. After the open bucket is resting on the ground downward movement of the dipstick is continued until the foot 28 on the lower end thereof seats on and bears against the radial members 44 on the upper surface of said bucket, as is shown in position B in FIG. 1. When the dipstick is thus positioned against the top of the bucket, the links 38, 39, and 40, which formerly supported said bucket, would normally tend to collapse but the aforementioned springs 36, and 48 within said stick and bucket members, respectively, hold said links taut within said members andV prevent the same from becoming tangled or fouled.

The Yhydraulic bucket rams 54 and S5 are then actuated to close the bucket, the pressure of the rigid dipstick Vagainst the upper surface of said bucket causing the bucket elements 50 and 51 to dig deeply into the soil in a pincher 0r vise action. The result is a positive downward digging force which permits the digging of harder soil in much less time than is possible with conventional excavators of comparable,Y size and power. Moreover, due to the fact that the present bucket is not rigidly connected to the dipstick, said bucket will automatically twist in the necessary direction in order to obtain the best bite or cut. Y K

When suicient earth has been collected the doubleacting rams 54 and 55 are operated to close the bucket and the valve to the ram 16 is opened to permit ow of fluid back to the reservoir. When said ram 16 has thus been released the hoist line 59 may be operated to raise the stick through the sleeve bearing 22 and the ram 32 actuated to swing the same upwardly and outwardly, as in position D in FIG. l. The boom may then be raised and swung laterally to a position over a dump truck or the like, and the rams 54 and 55 actuated to open the bucket and empty its contents therein. The boom and dipstick members are then re-positioned and lowered vfor the next bite or cut, and the operation repeated.

Due to the universally adjustable nature of the digging unit a wide variety of operative angles can be obtained with the present invention, as is illustrated by positions A, B, C, and D in VFIG. l, and it is unnecessary to constantly shift or maneuver the transport vehicle in order to obtain the desired cut, as is required with a conventional backhoe. In addition, and unlike conventional clam shell type excavators, with the present invention positive downward force can be applied to the digging bucket, thus not only increasing the eiciency of the excavator, but permitting the use of lighter, less expenlsive materialslin its construction. The result is a novel excavator which combines certain features of both the clam shell and backhoe types of excavators, but which improved machine is more eicient, less expensive in construction and operation, and which is designed to perform a geater variety of operations than either of said conventional machines.

With the above in mind, it is intended that the present invention include the embodiment illustrated and hereinbefore described, and any and all modifications or changes therein as may come within the spirit of the invention and Wtihin the scope of the following claims.

What I claim is:

l. In an excavator including a transport vehicle having a pivotally mounted boom projecting outwardly therefrom; a rigid dipstick pivotally connected to an outer portion of said boom and having a lower end with a pin; an earth handling implement having an upwardly facing portion forming a seat for coaction with said lower end of said dipstick; a link chain suspended from said pin on the lower end of said dipstick; and a pin to which the lower end of said chain is connected for normally supporting the implement in spaced, suspended position below said lower end of the dipstick, said chain and pin connection permitting the lower end of the dipstick to engage said earth handling implement seat when the implement is in engagement with the ground.

2. In an excavator including a transport vehicle having a pivotally mounted boom projecting outwardly therefrom; a rigid dipstick pivotally connected to an outer portion of said boom and having a lower end with a pin; an earth handling implement having an upwardly facing portion forming a seat for coaction with said lower end of said dipstick; a link chain suspended from said pin on the lower end of said dipstick; a pin to which the lower end of said chain is connected for normally supporting the implement in spaced, suspended position below said lower end of the dipstick, said chain and pin connection permitting the lower end of the dipstick to engage said earth handling7 implement seat when the implement is in engagement with the ground; and means whereby the position of one of said pins may be angularly changed to change the angular position of rotation of the implement with respect to the lower end of the dipstick.

3. An excavator comprising a transport vehicle; a boom universally pivotally mounted on and projecting outwardly from said vehicle; power means for pivoting said boom; a supporting member pivotally secured to the outer end of said boom; power means for pivoting said supporting member in a vertical plane; a rigid, hollow dipstick slidably carried in and extending through said supporting member; power means for raising and lowering said dipstick through said supporting member; a flexible coupling member secured to and depending below the lower end of said dipstick; spring means associated with said coupling member and adapted to maintain the same in a taut condition; a bucket secured to the lower end or said coupling member, said bucket normally being spaced below the lower end of said dipstick and including a pair of pivotal, clam shell digging elements, said clam shell elements being pivotal downwardly and inwardly toward each other to close the bucket; a double-acting hydraulic ram connected to each of said clam shell elements and to said bucket, said rams being adapted to open or close said clam shell elements; and remote control means for actuating said hydraulic rams.

4. An excavator comprising a transport vehicle; a boom universally pivotally mounted on and projecting outwardly from said vehicle and having sheaves on its outer end; remote control means for pivoting said boom; a iirst hydraulic ram secured to the outer end portion of said boom and extending longitudinally inwardly therealong, the inner, free end of said ram having a sheave thereon; a supporting member pivotally secured to the outer end of said boom; means for pivoting said supporting member in a vertical plane; a rigid, hollow dipstick slidably carried in and extending through said supporting member and having a sheave on its upper end; a bucket connected to the lower end of said dipstick and including a pair of clam shell digging elements, said clam shell elements being pivotal downwardly and inwardly toward each other to close the bucket; a double-acting hydraulic ram connected to each of said clam shell elements and to said bucket body, raid rams being adapted to swing said clam shell elements to either their open or closed position; remote control means for actuating said hydraulic rams; a hoist line connected to the transport vehicle and extending outwardly along the boom, said hoist line being trained over a sheave on the boom outer end and being anchored to the lower end of the dipstick, said hoist line being adapted to raise the dipstick through said supporting member; means for yactuating said hoist line; and aline anchored to the outer end portion of the boom and extended inwardly therealong and around the sheave on the inner end of said iirst hydraulic ram, said line then extending outwardly along the boom and around a sheave on the outer end thereof, upwardly and over the sheave on the upper end of the dipstick, and being anchored to said supporting member, said line being adapted to forcibly lower the dipstick through said supporting member upon extension of said iirst ram.

5. An excavator comprising a transport vehicle; a power winch on said vehicle; a boom universally-pivotally mounted on and projecting outwardly from said vehicle; remote control power means for pivoting said boom; a plurality of sheaves on the outer end of said boom; a iirst hydraulic ram secured to the outer end portion of said boom yand extending longitudinally inwardly therealong, the inner, free end of said ram having a sheave thereon; a supporting member pivotally secured to the outer end of said boom, said supporting member being pivotal in a vertical plane; a second hydraulic ram mounted on said boom and adapted to swing said supporting member about its pivot connection; a rigid dipstick slidably carried in and extending through said supporting member, said dipstick having a sheave on its upper end; a plurality of chain links supported from and normally depending below the lower end of the dipstick; spring means associated with said chain links and adapted to maintain the same taut; means in the dipstick lower end adapted to releasa'oly lock said chain in a selected position of rotation; a bucket to which the lower end of said chain is connected and including a pair of clam shell digging elements, said clam shell elements being pivotal downwardly and inwardly toward each other to close the bucket; a double-acting hydraulic ram connected to each of said clam shell elements and to said bucket body, said rams being adapted to swing said clam shell elements to either their open or closed position; remote control means for actuating said hydraulic rams; a hoist line connected to the power winch on said transport vehicle and extending outwardly along the boom, said hoist line being trained over the boom outer end and being anchored to the lower end of the dipstick, said hoist line being adapted to raise the dipstick through said supporting member; and a line anchored to the outer end portion of the boom and extending inwardly therealong and around the sheave on the inner end of said first hydraulic ram, said line then extending outwardly along the boom and under one of the sheaves on the outer end thereof, extending upwardly and over the sheave at the upper end of the dipstick, and being anchored to said supporting member, said line being adapted to forcibly lower the dipstick through said supporting member upon extension of said lirst ram.

6. In an excavator having a pivotally mounted boom projecting outwardly therefrom, a rigid dipstick pivotally connected to an outer portion of said boom, and having Ia lower end with an interior connector opening, an earthhandling implement having an upwardly facing portion forming a seat for coaction with said lower end of said dipstick, said seat having an opening and there being connector space below and communicating with said opening, a relatively short flexible connector having an upper end connected within said interiorropening of the lower'end of the dipstick and having a lower end extending through said opening in the seat of the implement and connected within the space below said opening, said exible connector being of'a relatively short length to permit flexible support ofthe implement in a position suspendedV only a short distance below the lower end of the dipstick, said flexible connector permitting said lower end of the dipstick to forcibly engagesaid implement seat when the implement is in engagement with the ground, and means for causing upper and lower portions of said exible connector to enter said connector opening and connector space when the parts are thus engaged so as not to interfere with said engagement.

7. In an excavator having a pivotally mounted boom projecting outwardly therefrom, a rigid dipstick pivotally connected to an outer portion of saidboom, and having a lower convex end with an interior connector opening, an earth-handling implement having an upwardly facing concave portion forming a seat for coaction with said convex lower end of said dipstick, said seat having an opening and there being connector space below and communicating with said opening, a relatively short exible connector having an upper end connected within Ysaid interior opening of the lower end of the dipstick and having a lower end extending through said opening in the seat of the implement and connected within the space below said opening, said flexible connector being of a relatively short length to permit flexible support of the implement in a position suspended only a short distance below the lower end of the dipstick, said flexible connector permitting said convex lower end of the dipstick to forcibly engage said concave implement seat when theimplement is in engagement with the ground, and means for causing upper 'and lower portions of said iiexible connector to enter said connector opening and'connector space when the parts are thus engaged so as not to interfere with said engagement.

8. VIn an excavator having a pivotally mounted boom projecting outwardly therefrom, a rigid dipstick pivotally connected to an outer portion of said boom, and having a lower end with an interior connector opening, an earth-handing implement having an'upwardly facing portion forming a seat for coaction with said lower end of said dipstick, said seat having an'opening andthere being connector space below and communicating withV said opening, a relatively short exible connector having an upper end connected within said interior opening of the lower end of the dipstick and having a lower end extending through said opening in the seat of the implement and connected within the space below saidV opening, said iiexible connector being of a relatively short length to permit flexible support of the implement in a position suspended only a short distance below the lower end of the dipstick, said exible connector permitting said lower end of the dipstick to forcibly engage said implement seat when the implement is in engagement with the ground, and means including a spring connected to at least one of said portions for causing upper and lower portions of said iexible connector to enter said connector opening and connector space when the parts are thus engaged so as not to interfere with said engagement.

9. In an excavator having a pivotally mounted boom projecting outwardly therefrom, a rigid dipstick pivotally connected to an outer portion of said boom, and having a lower end with an interior chain opening, an earthhandling implement having an upwardly facing portion Yforming a vseat for coaction with said lower end of said dipstick, said seat having an opening and there being chain space below and communicating with said opening, a chain having elongated links and having an upper link slidably connected within said chain opening of the lower end of the dipstick and having a lower link extending through said opening in the seat of the implement and slidably connected within the chain space below said opening, said chain comprising only a few links to permit flexible supportof the implement in a position suspended only a'short distance below the lower end of the dipstick, said chain permitting said lower end of the dipstick to forcibly engage said implement seatwhen the implement is in engagement with theY ground, and means for causing upper and lower portions of said chain Ato enter said chain opening and chain space when the parts are thus engaged so as not to interfere with said engagement. Y A

l0. In an excavator having aKpivotally mounted boom projecting outwardlyrtherefrom, a rigid dipstick pivotally connected to an outer portion of said boom, and having a lower end with an interior chain opening, an earthhandling implement having an upwardly facing portion forming a seat for coaction with said lower end of said dipstick, said seat having an opening and there being chain space below and communicating with said opening, a chain having elongated links and having an upper link slidably connected within said chain opening of the lower end of the dipstick and having a lower Vlink extending through said opening in the seat of the implement and slidably connected within the chain space below said opening, said chain comprising only a few links to permit liexible support of the implement in a position suspended only a short distance below the lower end of the dipstick, said chain permitting said lower end of the dipstick to forcibly engage said implement seatrwhen the implement is in engagement with the ground, and means includinga spring connected to at least one of said chain portions for causing upper and Vlower portions of said chain to enter said chain opening and chain space when the parts are thus engaged so as notto interfere with said engagement. p Y t .v

1l. In an excavator having a pivotally mounted boom projecting outwardly therefrom, a rigid dipstick pivotally connected to an outer portion of said boom, and having a lower end with an interior chain opening, a pin extending across said chain opening, an earth-handling implement having an upwardly facing portion forming aY seat for coaction with said lower end of said dipstick, said seat having an opening and there being chain space below and communicating with said opening, a pin lextending across said chain space, a chain having elongated links and having an upper link slidably connected by means of said pin within said chain opening of the lower end of the dipstick and having a lower link Aextending through saidV opening in theseat of the implement and slidably connected by means of said pin within the Vchain space below said opening, said chain comprising only a few links to permit flexible support of the implementtin a position suspended only a short distance below the lower end of the dipstick, said chain permitting said lower end of the dipstick to forcibly engageV said implement seat when the implement is in engagement with the ground, and means for causing upper and lower portions of said chains to enter said chain opening and chain space when the parts are thus engaged so as not to interfere with said engagement.

l2. In an excavator having a pivotally mounted boom projecting outwardly therefrom, a rigid Ydipstick pivotally connected to an outer portion of said boom, and having a lower end with an interior chain opening, an earthhandling implement having an upwardly facing portion forming a seat for coaction with said lower end of said dipstick, said seat having an opening and there being chain space below and communicating with said opening, aV link chain having an upper link slidably connected within said chain opening of the lower end of the dipstick and having Va lower link extending through said opening in the seat'of the Vimplement and slidably connected within the chain space below said opening, at least one of said slidable connections including a transverse pin, said chain comprising only a few links to permit Vflexible support of the implement in a position suspended only a short dis- 9 tance below the lower end of the dipstick, said chain permitting said lower end of the dipstick to forcibly engage said implement seat when the implement is in engagement with the ground, means for causing upper and lower portions of said chain to enter said chain opening and chain space when the parts are thus engaged so as not to interfere with said engagement, and means providing for change in the angular position of said pin to change the position of rotation of the implement with respect to the lower end of the (lipstick.

13. In an excavator having a pivotally mounted boom projecting outwardly therefrom, a rigid dipstick pivotally connected to an outer portion of said boom, and having a lower end with an interior connector opening, a tool having an upwardly facing portion forming a seat for coaction with said lower end of said dipstick, a relatively short iiexible connector having an upper end within said interior opening of the lower end of the dipsticl: and having a lower end connected to said tool, said iiexible connector being of a relatively short length to permit flexible support of the tool in a position suspended only a short distance below the lower end of the dipstick, said flexible connector permitting said lower end of the dipstick to forcibly engage said tool seat when the implement is in engagement with the ground, and means for taking up slack in said rlexible connector when the parts are thus engaged.

14. 1n an excavator having a pivotally mounted boom projecting outwardly therefrom, a rigid dipstick pivotally connected to an outer portion of said boom, and having a lower end, a tool having an upwardly facing portion forming a seat for coaction with said lower end of said dipstick, a relatively short llexible connector having an upper end connected to the lower end of the dipstick and having a lower end connected to said tool, said flexible connector being of a relatively short length to permit ilexible support of the tool in a position suspended only a short distance below the lower end of the dipstick, said exible connector permitting said lower end of the (lipstick to forcibly engage said tool seat when the implement is in engagement with the ground, and means for taking up slack in said iiexible connector when the parts are thus engaged.

15. In an excavator having a pivotally mounted boom projecting outwardly therefrom, a rigid dipsticx pivotally connected to an outer portion of said boom and having a lower end with an interior chain opening, a tool having an upwardly lacing portion forming a seat for coaction with the lower end of said dipstick, a chain having elongated links and having a lower link connected to said tool, means within said chain opening at the lower end of the dips ick for taking up slack in said chain, said chain comprising only a few links to permit exible support of the tool in a position suspended only a short distance below the lower end of the (lipstick, and said chain permitting said lower end or" the (lipstick to forcibly engage said tool seat when the tool is in engagement with the ground.

16. in excavator having a pivotally mounted boom projecting outwardly therefrom, a rigid (lipstick pivotally connected to an outer portion of said hoorn and having a lower end with an interior chain opening, a pin extending across said chain opening, a tool having an upwardly facing portion forming a seat for coaction with said lower end of said (lipstick, a transverse pin on said tool extending through a lower link of said chain, means in said chain opernng at the lower end of the dipstick connected to an upper link or" said chain for taking up slack, said chain comprising only a few links to permit ilexible support of the tool in a position suspended only a short distance below the lower end of the (lipstick, said chain permitting the lower end of the dipsticlr to engage said tool seat when the tool is in engagement with the ground.

References Cited in the ille of this patent UNITED STATES PATENTS 368,729 Morris Aug. 23, 1887 513,824 Pilcher lan. 30, 1894 1,296,201 Mcll/lyler Mar. 4, 1919 1,463,090 Nafziger Oct. 7, 1920 2,755,946 Bevan July 24, 1956 2,796,180 Rose lune 18, 1957 2,914,203 Gainer Nov. 24, 1959 2,989,198 Bradley lune 20, 1961 

1. IN AN EXCAVATOR INCLUDING A TRANSPORT VEHICLE HAVING A PIVOTALLY MOUNTED BOOM PROJECTING OUTWARDLY THEREFROM; A RIGID DIPSTICK PIVOTALLY CONNECTED TO AN OUTER PORTION OF SAID BOOM AND HAVING A LOWER END WITH A PIN; AN EARTH HANDLING IMPLEMENT HAVING AN UPWARDLY FACING PORTION FORMING A SEAT FOR COACTION WITH SAID LOWER END OF SAID DIPSTICK; A LINK CHAIN SUSPENDED FROM SAID PIN ON THE LOWER END OF SAID DIPSTICK; AND A PIN TO WHICH THE LOWER END OF SAID CHAIN IS CONNECTED FOR NORMALLY SUPPORTING THE IMPLEMENT IN SPACED, SUSPENDED POSITION BELOW SAID LOWER END OF THE DIPSTICK, SAID CHAIN AND PIN CONNECTION PERMITTING THE LOWER END OF THE DIPSTICK TO ENGAGE SAID EARTH HANDLING IMPLEMENT SEAT WHEN THE IMPLEMENT IS IN ENGAGEMENT WITH THE GROUND. 